Step 1

Heat the oven to 400°F. Coat a 9x13-inch baking dish with cooking spray.

Step 2

Heat 1 teaspoon neutral oil in a large skillet over medium-high heat until shimmering. Add 1 1/2 pounds lean ground beef, 1/4 teaspoon kosher salt, and 1/4 teaspoon black pepper. Cook, breaking up the meat into bite-size pieces, until cooked through and no longer pink, 8 to 10 minutes.

Step 3

Transfer the meat to the baking dish. Add 2 (10.5-ounce) cans condensed cream of mushroom soup, 1/2 cup sour cream, and 2 ounces shredded sharp cheddar cheese (about 1/2 cup). Stir to combine. Spread into an even layer. Arrange 1 (10-ounce) bag frozen cut green beans in an even layer over the soup mixture. Arrange 24 to 32 ounces frozen tater tots on top in an even layer.

Step 4

Bake for 20 minutes. Sprinkle evenly with the remaining 6 ounces shredded sharp cheddar cheese (1 1/2 cups). Continue baking until the filling is bubbling around the edges, the cheese on top is melted, and the tater tots are golden-brown, 15 to 20 minutes more.